1. Field of the Invention
The present invention relates to network elements and, more particularly, to a method and apparatus for managing interfaces on a network element.
2. Description of the Related Art
Data communication networks may include various computers, servers, nodes, routers, switches, hubs, proxies, and other network devices coupled to and configured to pass data to one another. These devices will be referred to herein as “network elements.” Data is communicated through the data communication network by passing data packets (or data cells, frames, or segments) between the network elements by utilizing one or more communication links between the devices. A particular packet may be handled by multiple network elements and cross multiple communication links as it travels between its source and its destination over the network.
FIG. 1 illustrates one example of a communication network 10. As illustrated in FIG. 1, subscribers 12 access the network by interfacing with Provider Edge (PE) network element 14. The provider edge network element collects traffic from the subscribers and multiplexes the traffic onto the network backbone, which includes multiple Provider (P) network elements 16 connected together. Through an appropriate use of protocols and exchanges, data may be exchanged with another subscriber or resources may be accessed and passed to the subscriber 12.
The various network elements on the communication network communicate with each other using predefined sets of rules, referred to herein as protocols. Multiple protocols exist, and are used to define aspects of how the communication network should behave, such as how the computers should identify each other on the network, the format that the data should take in transit, and how the information should be reconstructed once it reaches its final destination. Examples of several protocols include Asynchronous Transfer Mode (ATM), Frame Relay (FR), Ethernet, Transport Control Protocol (TCP), Internet Protocol (IP), Point-to-Point Protocol (PPP), and Multi-Protocol Label Switching (MPLS), although there are probably more than 100 other protocols as well that may be used to govern aspects of communications taking place over links on the network. Depending on the type of services to be provided to the customer, different protocols may be required to be used by the provider to carry the subscriber's traffic on the network 10.
Network elements may include many ports, each of which may be connected to one or more physical links operating using one or more protocols. For example, the provider edge network element 14 may connect with the subscribers over different physical links connected to different physical ports. Interfaces on a network element represent a mapping between an application and one or more of the ports. For example, a given application may need an interface to carry Ethernet traffic across an IP-based Virtual Private Network tunnel. The interface may require access to one or more of the network element's physical ports. By configuring an interface on the network element, the network element's physical resources may be abstracted so that applications and services can use the interfaces to obtain access to the network element's physical resources.
Interface management relates to how interfaces are created, used, managed, and destroyed on a network element. Conventionally, interfaces were created at a central interface controller and, once the interfaces were created, the interface information was passed out to the port cards so that the ports could be configured to handle traffic according to the interface definition. This system had several drawbacks. For example, configuring all of the interfaces on a network element from a central card created a bottleneck, as a given network element may be required to support thousands or tens of thousands of interfaces. This limits scalability of the network element. Additionally, the central interface management system created a single point of failure which was required to be replicated to provide redundancy in the interface management system, thus increasing costs and complicating the management system by requiring the exchange of information between the redundant central interface control systems.